Doctor blade for calender roll



Feb. 25, 1964 G. BINKOWSKI 3,122,090

DOCTOR BLADE FOR CALENDER ROLL Filed June 11, 1962 3 Sheets-Sheet 1 Feb. 25, 1964 G. BINKOWSKI 3,122,090

DOCTOR BLADE FOR CALENDER ROLL Filed June 11, 1962 3 Sheets-Sheet 2 e i ws Feb. 25, 1964 e. BINKOWSK] 3,122,090

DOCTOR BLADE FOR CALENDER ROLL Filed June 11, 1962 3 Sheets-Sheet 3 INVENTOR BY M WW ATTORNEY5 United States Patent 3,122,090 DUCTGR BLADE FOR CALENDER ROLL George Binkowski, Derby, Conn, assignor to Farrel- Birmingham Company, Incorporated, Ansonia, Conn, a corporation of Connecticut Filed lane 11, 1%2, Ser. No. 201,379 9 a'ilaims. (Ql. tea-res) This invention relates to calendering machines and to a doctor blade which cleans the roll of contaminants, such as bits or" paper or other material being rolled. Particularly, the invention relates to a doctor blade positioning mechanism for use in a calendering machine which is provided with movable calender rolls. The invention is directed toward maintaining the axial relationship between a calender roll and its doctor blade.

In calendering it is known that the calender should be provided with means to adjust the nip pressure between adjacent rolls along the length thereof to be certain that the rolled product will have a uniform thickness at the middle and the ends. Such means usually take the form of rOll crown with a roll usually being slightly thicker in the middle than at the ends. Since it may be desirable to change nip pressure or compensate for the weight of added rolls which may be provided to increase the number of roll passes, it is preferable to have the crown variable. This could be done by changing one crowned roll for another having a difierent crown as required for the particular application. However, this is usually not practical or economically feasible and other means have been devised for changing the effective crown.

One such means is to cross the axes of adjacent rolls thereby providing greater surface spacing at the ends than at the center of the roll surfaces. An example of means for crossing the axes is shown in US. Patent No. 2,965,920. Reference to such patent will readily show that crossing the roll axes will, in effect, change the roll crown as required for difierent applications.

When calendering material, such as paper, bits of material cling to the rolls. For the highest quality calendering, it is necessary that the roll surfaces be kept in a clean condition and this has been accomplished by providing a doctor blade for each roll which contacts the roll surface along its entire length and strips the contaminants from the surface during calendering. Of course, for proper stripping without damaging the roll, it is mandatory that the longitudinal axis of the doctor blade be parallel to the central axis of the roll.

While means for crossing roll axes and means for stripping contaminants from roll surfaces are not new, the combination of such means has not heretofore been accomplished in a simple and effective manner.

Accordingly, it is a primary object of this invention to provide a calender having means for crossing roll axes and means for stripping contaminants from the roll surfaces With simple and efiective means for maintaining parallelism between the longitudinal axis of the stripping means and the central axis of the roll regardless of the amount of crossing the roll axes, within the practical limits of axial crossin In machines of this type, the rolls are usually stacked vertically and the bottom roll may be provided with a crown. The other rolls in the stack, including the top roll, may also be crowned. In the usual operation it may only be necessary to vary the efiective crown of one of aizznaa Patented Feb. 25, 1&54

the rolls, such as the bottom roll or top roll, and this may be accomplished by moving the bottom roll, for example, so that its axis crosses the axis of the roll immediately above it. This may be done by moving the journals at both ends of the bottom roll by equal amounts in opposite directions so that the axis of the bottom roll crosses the axis of the adjacent roll. Journal movement may be effected by moving the journal hearing or the journal box in a linear direction perpendicular to the roll axis. By moving the journals in opposite directions the roll will, in effect, be pivoted about a diametrical line passing through the roll midway between the roll ends.

The doctor blade is mounted in axial bearings at opposite ends thereof and these bearings must also move in opposite directions to maintain the doctor blade parallel to the roll axis. However, the doctor blade bearings usually may not be mounted for movement along the same line as the roll journal bearings or boxes. Therefore, the radius for scribing the are through which the roll journals move is not the same as the radius for scribing the are through which the doctor blade bearings move. Thus, imparting equal linear motion to the roll journal and doctor blade hearing will move them through arcs generating different angles. Generally speaking, the invention is directed to providing linkages for moving the doctor blade hearings in response to movement of the roll journals so that the angle generated by the arcuate movement of the roll journals will be the same as the angle generated by the arcuate movement of the doctor blade bearings.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts Which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the invention, reference is bad to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of a portion of the left Side of a calendering machine showing two calendering rolls and the relationship of the elements in accordance with the invention;

FIG. 2 is a partial left side elevational view of the elements shown in FIG. 1, with certain portions being broken away for the sake of clarity;

FIG. 3 is a partial sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a partial sectional View taken along line 44 of FIG. 3;

FIG. 5 is a partial sectional view taken along line 55 of FIG. 3;

FIG. 6 is a schematic representation of a calender roll having movable journals; and

FIG. 7 is a schematic representation of the doctor blade linkage mechanism in accordance with the invention.

For the sake of simplicity, the drawings show only a portion of the left side of a calendering machine, it be ing understood that, for the purposes of this invention, mechanism similar to that shown is provided at the right side of the machine.

Referring now to FIG. 1, a calendaring machine is provided with a frame 3.1 carrying at least two calender rolls l2 and 13. Lower roll 12, which is shown as the bottom roll, is rotatably mounted in a suitable journal box 14 while upper roll 13 is mounted in bearings 15 in a support plate 16. Support plate 16 is pivoted to frame 11 at 17 so that the upper calender roll may rest on the bottom roll. Journal box 14 is slidably mounted to frame 11 and a drive mechanism 18 is provided to slide the journal box with relation to the frame. A doctor blade 19 is mounted adjacent the surface of roll 12 and is supported as will hereafter be described.

Referring now to FIGS. 2 and 3, roll 12 is provided with a journal portion 21 which is rotatably mounted in a bearing 22 which may be of the frictionless type. Bearing 22 is supported in journal box 14 and the journal box is mounted to a slide 23. Slide 23 is slidably mounted in a guide 24 carried by the frame. A drive screw 25 threadedly engages slide 23 and is driven by any suitable drive mechanism 18 mounted to the frame. One such drive mechanism 18 may be an electric remote-control motor which rotates drive screw 25 by means of suitable gearing. it will be seen that roll journal 21 can be moved to the left or right, as shown by the arrow in FIG. 2, by means of the drive mechanism. The movement of slide 23 in guide 24 will be linear and substantially perpendicular to the central axis of calender roll 12.

Since the journal on the opposite end of roll 12 (not shown) will be moved the same amount but in the opposite direction by similar mechanism concurrently with movement of journal 21, and since the movement of the journal boxes will be linear, it is necessary that a slight amount of pivotal .motion be provided between the roll journal and slide 23. Where the journal bearings are spherical roller anti-friction bearings, the bearing rollers will normally permit the required pivotal motion. However, a pivot pin 26 can be provided between journal box 14 and slide 23 to allow the journal box a small amount of pivotal motion with respect to the slide as the slide is repositioned for other types of non-self-aligning bearings.

Referring now to FIGS. 3, 4 and 5, doctor blade 19 is mounted to contact the surface of roll 12, the nonnmal direction of roll rotation being shown by the arrow in FIG. 4. The doctor blade is supported by an L-member 31 having a journal 32 at each end '(one only being shown). Journal 32 is rotatably and pivotally mounted in a bearing housing 33 which is supported by an arm 34. A pair of links 35 and 36 are pivoted at their lower ends to frame 11 by means of fins 37 and 38, respectively. The upper ends of the links are provided with elongated slots 41 land 42 through which they are pivoted to slide 23 by means of pins 43 and 44, respectively. 34 is pivoted at its ends to links 35 and 36 intermediate its ends, pivot pins 45 and 46 being provided for that purpose.

In order to apply sufiicient pressure to doctor blade 19 to keep it in contact with the surf-ace of roll 12 to efiectively strip the contaminants from the roll, a pressure cylinder 48 is mounted between an arm 54 attached to frame 11 and L-member 31. The pressure in the cylinder rotatably urges doctor blade 19 into contact with the surface of roll 12 around journal 32. Means are also provided for axially reciprocating the doctor blade so that the blade does not run continuously against the same portion of the roll and cause localized grooving of the roll. As an example of one such means, a drive shaft 51 'is rotatably mounted in a suitable mechanism, indicated at 52, which may be driven by a motor 53. Mechanism 52 is mounted to arm 54. The end of drive shaft 51 is provided with a cam 55 which engages between the parallel walls of fingers 56 attached to and extending from L-member 31. By reference to FIG. it'can be seen that rotation of cam 55 will cause L-member 31 and the doctor blade connected thereto to be reciprocated in the direction shown by the arrow in that figure. Reciprocatlon is possible since bearing housing 33 also provides sliding support for journal 32.

7 As shown in FIGS. 3 and 4, when drive mechanism '18 moves slide 23 to the left or right, links 35 and 36 will be pivoted about pins 37 and 33 by cooperation of 4i pins 43 and 44 elongated slots 41 'and 42. The provision of the elongated slots is necessary since slide 23 may only move in a straight line while links 35 and 36 move in arcuate paths. Movement of links 35 and 36 causes arm 34 to be moved parallel to slide 23 by means of pins 45 and 46 thereby moving bearing housing 33 and the doctor blade. P ince movement of the doctor blade is imparted by movement of slide 23, which also effects the movement of journal 21, the displacement of the doctor blade will be directly proportional to the displacement of the roll journal.

Referring now to FIGS. '6 and 7, conjunction with FIGS. 3 and 4, and particularly to the schematic diagram of FIG. 6, it will be seen that the slides cause movement of the journals at each end of the roll along lines ab, thereby pivoting the roll around po nt 0. Since the doctor blade journals are mounted inboard of the roll journals, the doctor blade journals will be moved along lines ed. Let L by the distance from pivot 0 to point a on the roll journal and R be the distance of movement from a to b. In moving the distance R the axis of the roll be displaced from line aa to line bb. Letting L be the distance from the pivot i) to the doctor blade journal 0, movement of the doctor blade journal through the distance R will move the journal from c to x, thereby displacing the doctor blade along the line xx. FIG. 6 clearly shows that line xx is not parallel to line bb and that order to maintain the doctor blade parallel to the roll it is necessary that the doctor blade journal be moved along the line from c to d which lies on the line bb. This distance may be called R Referring to FIG. 7, the links 35 and36 are pivoted about pins 37 and 38 and pins 43 and 44 will move the links from a to b through the horizontally projected distance R the distance from pin 37 to pin 43 being S Pin 45 which is the distance S from pin 37 will move through an are from c to d by the distance R thereby reciprocating the doctor blade journal a lesser amount than the roll journal.

If the angle through which the roll is pivoted is 0, the following expression will hold true:

an L L If the angle through which pin 43 is pivoted around pin 37 is a then the following expression may be derived:

tan 0:

Thus, by substitution it is'clear that and if these proportions are carefully observed, 'movement of the roll to effect crossing of the axis of the roll with the axis of the adjacent roll will automatically move the doctor blade the proper amount to maintain its longitudinal axis parallel to the axis of the roll which it contacts.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, areefliciently attained and, since certain changes the scope of the invention which, as a matter of language,

might be said to fall therebetween.

What is claimed is: 1. In a calender having at least two adjacent calender rolls, means for maintaining axial parallelism between a movable calender roll and its doctor blade comprising a frame, a first calender roll, journal means rotatably supporting said calender roll at each end thereof, said journal means being slidably mounted to said frame along lines substantially perpendicular to the central axis of said calender roll for crossing the axis of said calender roll with relation to the axis of the adjacent calender roll, a doctor blade in contact with the surface of said first calender roll, support means connected to said doctor blade and said frame for supporting said doctor blade on said frame, and means cooperatively connecting said support means to said journal means for moving said support means and said doctor blade in response to the movement of said journal means relative to said frame for maintaining the longitudinal axis of said doctor blade portion to the central axis of said first calender roll at any position of said first calender roll.

2. in a calender having at least two adjacent calender rolls, means for maintaining axial parallelism between a movable calender roll and its doctor blade comprising a frame, a first calender roll, journal means rotatably supporting said calender roll at each end thereof, said journal means being slidably mounted to said frame along lines substantially perpendicular to the central axis of said calender roll for crossing the axis of said calender roll with relation to the axis of the adjacent calender roll, said journal means including means for sliding the ends of said calender roll by equal arnounts in opposite directions to effect axis crossing, a doctor blade in contact with the surface of said first calender roll, said doctor lade having journals at each end thereof, bearing means rotatably and pivotally supporting said doctor blade journals, support means connected to said bearing means and said frame for supporting said doctor blade on said frame, and means cooperatively connecting said support means to said journal means for moving said support means and said doctor blade journals in response to the movement of said journal means relative to said frame during sliding movement of said journal means for maintaining the longitudinal axis of said doctor blade parallel to the central axis of said first calender roll.

3. In a calender having at least two adjacent calender rolls, means for maintaining axial parallelism between a movable calender roll and its doctor blade comprising a frame, a first calender roll, a roll journal on each end of said calender roll, a slide slidably mounted to said frame adjacent each of said roll journals, means rotatably and pivotally mounting said roll journals to said slides, drive mechanisms mounted to said frame and cooperatively en gaging each of said slides to slide said roll journals by equal amounts but in opposite directions with relation to said frame along lines substantially perpendicular to the central axis of said calender roll for crossing the axis of said calender roll with relation to the axis of the adjacent calender roll, a doctor blade in contact with the surface of said first calender roll, journals on said doctor blade at each end thereof, bearing means rotatably and pivotally supporting each of said doctor blade journals, and a pair of linkages, one pivoted to each of said bearing means, said slides and said frame for moving said doctor blade with reference to said frame under the urging of the sliding movement of said slides, the juxtaposition of the pivot points Wit 1 relation to one another being such that the longitudinal axis of said doctor blade is maintained parallel to the central axis of said first calender roll.

4. A linkage for imparting motion to a calender roll doctor blade by means of lineal movement of the roll journal supported by a slide slidably mounted to a calender frame, the linkage comprising a pair of parallel links each pivoted at one end to the calender frame and at the other end to the slide, and a cross arm pivoted at its ends to said links, said cross arm supporting the doctor blade, the ratio of the distances along a link from the slide pivot to the frame pivot as compared with the distance from the cross arm pivot to the frame pivot being equal to the ratio of the distances measured between the axial center of the calender roll and the pivotal center of the roll journal as compared with the distance from the longitudinal center of the doctor blade to the pivotal center of the doctor blade at the doctor blade journal.

5. The structure defined in claim 3 and further including resilient means operatively engaging said doctor blade to yieldably maintain said doctor blade in contact with the surface of said calender roll, said resilient means comprising a cylinder mounted to said frame, a piston slidably mounted in said cylinder, hydraulic fluid under pressure in said cylinder urging said piston outwardly from said cylinder, and a piston rod attached at one end to said piston and at the other end to said doctor blade whereby the hydraulic pressure acting on said piston urges said doctor blade into contact with said calender roll.

6. The structure defined in claim 3 and further including means mounted to said frame and cooperatively engaging said doctor blade for reciprocating said doctor blade along its longitudinal axis to prevent said doctor blade from running continuously against the same portion of said calender roll surface.

7. In a calender having at least two adjacent calender rolls, means for maintaining axial parallelism between a movable calender roll and its doctor blade comprising a frame, a first calender roll, a roll journal on each end of said calender roll, a slide slidably mounted to said frame adjacent each of said roll journals, a journal box mounted to each of said slides, a bearing mounted in each of said journal boxes and supporting one of said roll journals, means being provided to permit pivotal movement between said roll journal and said slide, drive mechanisms mounted to said frame and cooperatively engaging each of said slides to slide said roll journals by equal amounts but in opposite directions with relation to said frame along lines substantially perpendicular to the central axis of said calender roll for crossing the axis of said calender roll with relation to the axis of the adjacent calender roll, a doctor blade in contact with the surface of said first calender roll, a support-member carrying said doctor blade, said support-member being provided with journals on each end thereof, journal boxes carrying bearings rotatably and pivotally supporting each of said support-member journals, and a pair of linkages, one pivoted to each of said support-member journal boxes, said slides and said frame for moving said support-member journals with reference to said frame under the urging of the sliding movement of said slides, the juxtaposition of the pivot points with relation to one another being such that the longitudinal axis of said doctor blade is maintamed to the central axis of said first calender roll.

8. The structure defined in claim 7 wherein each of sand pair of linkages comprises a pair of parallel links each pivoted at one end to said frame and at the other end to said slide, and a cross arm pivoted at its ends to said links, said cross arm being mounted to said support member journal box, the ratio of the distances along a link from the slide pivot to the frame pivot as compared with the distance from the cross arm pivot to the frame pivot being equal to the ratio of the distance measured between the axial center of said calender roll and the pivotal center of said roll journal as compared with the d1stance from the longitudinal center of said doctor blade to the pivotal center of said support-member ournal.

9. In a calender having a frame, a calender roll with ournals movable with respect to said frame and having a doctor blade in contact with the surface of the calender roll, means cooperating with said doctor blade and responsive to the movements of the calender roll journals for moving said doctor blade proportionately to the movement of the roll journals so that the longitudinal axis of said doctor blade is maintained parallel to the central '7! axis of said calender roll, said means comprising an arm at each end of said roll, each arm being pivoted at a first pivot to said frame, at a second pivot to said roll journals and at a third pivot to said doctor blade, said third pivot supporting said doctor blade with reference to said frame 5 and moving said doctor blade as said arm is pivoted on said frame responsive to movement of said roll journals, said pivot points being related one to another in such a manner that the angular movement transmitted to said v doctor blade is equal to the angular movement of said roll.

References fitted in the file of this patent UNITED STATES PATENTS 242,753 Chambers June 14, 1881 1,144,802 Wan'en June 29, 1915 2,762,295 Varga et al Sept. 11, 1956 2,965,920 Whittum Dec. 27, 1960 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3,122,090 February 25 1964 George Binkowski It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 19, for "by" read be column 5 line 17, for "portion" read parallel column 6, line 53, before "to" insert parallel Signed and sealed this 7th day of July 19640 (SEAL) Attest:

ERNEST W; SWIDER Aitesting Officer EDWARD J. BRENNER Commissioner of Patents 

1. IN A CALENDER HAVING AT LEAST TWO ADJACENT CALENDER ROLLS, MEANS FOR MAINTAINING AXIAL PARALLELISM BETWEEN A MOVABLE CALENDER ROLL AND ITS DOCTOR BLADE COMPRISING A FRAME, A FIRST CALENDER ROLL, JOURNAL MEANS ROTATABLY SUPPORTING SAID CALENDER ROLL AT EACH END THEREOF, SAID JOURNAL MEANS BEING SLIDABLY MOUNTED TO SAID FRAME ALONG LINES SUBSTANTIALLY PERPENDICULAR TO THE CENTRAL AXIS OF SAID CALENDER ROLL FOR CROSSING THE AXIS OF SAID CALENDER ROLL WITH RELATION TO THE AXIS OF THE ADJACENT CALENDER ROLL, A DOCTOR BLADE IN CONTACT WITH THE SURFACE OF SAID FIRST CALENDER ROLL, SUPPORT MEANS CONNECTED TO SAID DOCTOR BLADE AND SAID FRAME FOR SUPPORTING SAID DOCTOR BLADE ON SAID FRAME, AND MEANS COOPERATIVELY CONNECTING SAID SUPPORT MEANS AND SAID JOURNAL MEANS FOR MOVING SAID SUPPORT MEANS AND SAID DOCTOR BLADE IN RESPONSE TO THE MOVEMENT OF SAID JOURNAL MEANS RELATIVE TO SAID FRAME FOR MAINTAINING THE LONGITUDINAL AXIS OF SAID DOCTOR BLADE PORTION TO THE CENTRAL AXIS OF SAID FIRST CALENDER ROLL AT ANY POSITION OF SAID FIRST CALENDER ROLL. 